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The Ag-mixed $${\text{Se}}_{70}{\text{Te}}_{30}$$ thermally deposited semiconducting thin films show interesting thermoelectric properties. As the Ag content in the structure of $${\text{Se}}_{70}{\text{Te}}_{30}$$ increases, the Seebeck coefficient increases. The semiconductive thin films reveal a p-type behavior. The dark conductivity increases at 300 K, whereas a reduction in $$\text{c}\text{o}\text{r}\text{r}\text{e}\text{s}\text{p}\text{o}\text{n}\text{d}\text{i}\text{n}\text{g}$$ activation energy for dark, photo and thermal response is observed with the increase in the Ag content. It is elucidated that the power factor for $${\left({\text{Se}}_{70}{\text{Te}}_{30}\right)}_{100-x}{\text{Ag}}_{x} (0.0\le x \le 8.0\; {\text{at}}.{\%})$$ semiconducting thin films can be tuned and enhanced at varied temperature ranges through adjusting the addition amount of Ag. These results indicate that these semiconducting thin films have remarkable potential as thermoelectric generators.

In the present scenario, ferrites are widely used for humidity sensor applications. Aiming this, we have prepared Dy3+-doped Mn–Zn ferrites by solution combustion method combining urea and glucose as burning agent. And obtained powder was characterized by several physicochemical techniques. The phase purity was confirmed by using the techniques such as X-ray powder diffraction and infrared spectroscopy. FTIR spectra show 2 prominent absorption bands under 1000 cm−1 which confirms the formation of spinel ferrite. The dielectric studies with change in frequency exhibited remarkable changes with Dy3+ content in samples. All electrical responses were investigated as a function of frequency and Dy3+ content at room temperature. The dielectric constant and loss on the frequency of the alternating applied electric field is consistent with Maxwell–Wagner style interfacial polarization. Further Humidity sensing response were recorded for pellet samples. It is noteworthy that, as the composition of the Dysprosium (Dy3+) increases the resistance is enhanced and is maximum for the Mn0.5Zn0.5Dy0.03Fe2−0.03O4 composite. Hence our results are good enough for sensor applications.

Alkali boro-bismuthate glasses modified with MoO3 were explored using DTA. The activation energies for glass transition (Eg) and crystallization (Ep) were evaluated using the heating rate dependence of the glass transition temperature (Tg) and the peak temperature of crystallization (Tp), respectively. The study indicated a decrease in Tg, Tp, Eg, and Ep as a function of the MoO3 and Bi2O3 contents. This decrease is ascribed to changes in the alkali borate network. XRD was used to confirm the results of this study. The XRD analysis revealed the existence of crystalline phases such as Na2B4O7, Bi2MO6, and B1.5Mo0.25O3 in the amorphous alkali borate network. The kinetic exponents n and m that determine the crystallization reaction mechanism in the glasses were obtained using the experimental values of the crystallized volume fraction (χ). With the increase in x content, the n values decrease, which may be ascribed to the transformation from the three-dimensional network to the one-dimensional network, which decreases $$E_{p}$$ values and crosslink density.

Pr2O3 doped bismuth-phosphate glasses have been produced via an ordinary melt quenching tool. Glasses have a chemical content (5–x) Al2O3–15Na2O–20Bi2O3–60 P2O5 –xPr2O3 with x values between 0 and 2 mol%. The structural and mechanical features of the prepared phosphate-based glasses were investigated. The XRD spectra confined the amorphous type of these glasses. Furthermore, the influence of Pr2O3 on the mechanical features has been explored and related to the structure. The relationship between structural variations and the contents of Pr2O3 has been investigated in terms of FTIR and by the determination of the density and the ultrasonic velocity. The density and the ultrasonic velocities were utilized to calculate the elastic moduli of the glasses. The acquired results indicate that the ultrasonic velocity and the elastic moduli increase as a function of Pr2O3 in the whole explored studied glasses. The analysis of FTIR spectra refers that Pr2O3 is interstitial settled in the phosphate network with [PrO7] associated with covalent Pr–O–P bonds, whereas Bi2O3 and Al2O3 settle on the network with [BiO6], and [AlO6] units. These experimental features coincide with a compact structure and act in a manner that Pr2O3 incorporates the glassy network with plenty of bridging oxygen atoms. These arguments encourage the use of these glasses in radiation shielding materials.

The Co0.5Ni0.5CexSmyFe2-x-yO4 (CNCSF) XRD pattern revealed the purity of the samples without any secondary phase. The crystallite size CNCSF are in nano range. Further, the calculated lattice parameter of CNCSF are found to increasing with the RE content. From SEM micrographs surface morphology and the microstructure of the CNCSF was studied. The porous nature of the samples is revealed by SEM, which will aid in increasing their sensing response. Energy dispersive X-ray spectroscopy (EDS) patterns have confirmed the stoichiometric presence of Co2+ Ni2+, Ce3+, Sm3+ and Fe3+, those are used to prepare the CNCSF. The dielectric behaviour is similar to that of conventional spinel ferrite structures, in that the dielectric constant is highest at low frequencies and decreases at higher frequencies due to electron hopping, resulting in dielectric dispersion. Only one semicircle is seen in each Cole-Cole plot, which has uncovered that the contribution to conductivity is predominantly from the grain boundaries. At room temperature, the gas sensing responses of CNCSF thin films were investigated. For liquified petroleum gas (LPG), the gas sensing characteristics of the prepared thin films were investigated. At room temperature, the x = 0.03 thin films showed excellent sensitivity to liquified petroleum gas. The sensing response and recovery time of all of the thin films that had been prepared were reported. The sensing response of x = 0.03 thin films was highly stable over a period of 60 days on exposure to LPG (1000 PPMv), according to the stability analysis. The sample thin film with x = 0.03 can be utilized in gas sensor technology, particularly for the detection of LPG at room temperature, due to its increased sensitivity, quick response and recovery times, and stability.

Quartz was used as a substrate to hold different film thicknesses of Ge0.15Te0.78Cu0.07 within range 100–500 nm prepared by thermal evaporation technique. Films are still amorphous up to 200 nm and turn to more ordered nano polycrystalline one by ascending the values of film thickness up to 500 nm. Films turn to crystalline phase due to annealing. The relation of resistance and temperature shows phase transformation. Optical constants; refractive index, n absorption coefficient, α single-oscillator energy, Eo dispersion energy, Ed lattice dielectric constant, εL infinite wavelength dielectric constant, ε∞ the ratio of the carrier concentration to the effective mass, N/m∗ optical conductivity, σ and energy loss function, ELF show decreasing values with thickness up to 200 nm followed by ascending values within range 200–500 nm. It is concluded that the thickness range 100–200 nm introduces more disordered films while 200–500 nm introduces more ordered one. Keywords: GeTeCu alloys, Structural properties, Optical properties, Thickness, Nano materials, Phase change memory

250 nm thickness of meso nickel (II) tetraphenyl-21H, 23H-porphyrin, NiTPP films were prepared by thermal evaporation technique on a quartz substrate. The prepared films were illuminated for 10, 20, 30, 60, 120, 240, 360 and 420 min. Films of 120 and 240 min of illumination time had been affected while others had no response. The as prepared meso NiTPP films are amorphous and the illuminated one are crystalline with amorphous background included within nano scale. The illuminated films were accompanied by photo bleaching effect. Two gaps could be distinguished; indirect optical gap, E gi opt and the fundamental energy gap, Eg. Optical parameters; refractive index, absorption coefficient, single-oscillator energy, dispersion energy, Lattice dielectric constant, the ratio of the carrier concentration to the effective mass, optical conductivity and energy loss function were studied. All mentioned parameters were affected by the illumination time. The response of nano meso NiTPP films to the mention illumination time has pulse shape, so it is recommended to be used as optical sensor.

Se–Te materials have shown promise in optoelectronic applications. A combination of enhanced optical and mechanical properties represents a good candidate for optical limiting devices. Here, we report the influence of Ag additive on the optical and mechanical properties of ( S e 70 T e 30 ) 100 − x A g x ( 0.0 ≤ x ≤ 8.0 a t . % ) chalcogenide thin films. The reflectance spectra of amorphous thin films have been analyzed in the spectral range 0.3 μm–2.5 μm. The optical parameters are obtained using reflectance spectra of the thin films. The refractive index increases with the addition of Ag, while the optical band gap decreases from 1.40 eV to 1.11 eV. The reduction in the optical band gap is correlated with the raise in the concentration of defect states and the disorder. The nonlinear refractive index and nonlinear susceptibility have been evaluated and found to show an augmented response with Ag content. The value of ( χ ( 3 ) ) increases from 3.44 × 10−11 esu to 7.66 × 10−11 esu and n2 from 3.98 × 10−10esu to 8.08 × 10−10esu. The mechanical properties have also been analyzed theoretically and ultrasonically with Ag incorporation to SeTe thin films.

The physical properties of Ag doped Se based ternary glassy alloys have been examined theoretically. (Se70Te30)100-xAgx (0.0 ≤ x ≤ 8.0) chalcogenide alloys have been prepared by quenching method. The results show that the system is in floppy mode having constant average coordination number 2. The estimated density shows an increase with the Ag content. The mean bond energy and glass transition temperature vary in a similar fashion with an increment in Ag atomic % in the Se-Te system. The value of cohesive energy (1.91eV/mol to 1.97 eV/mol) and average bond strength (24.19 kcal/mol to 25 kcal/mol) has shown increasing trend in the system. From the results of the investigated samples, the covalency parameter > 90%. So, it can be assumed that compositions are stable glass formers and may be used in the infrared system.

This work brings out the importance of precursors (AgNO3, AgCl, and AgI) that involve in tailoring the optical properties for the Au-Ag bimetallic nanoparticles doped in the dichroic glasses. The incorporation of silver nanoparticles in 20Li2O-15CaF2-20ZnO-45B2O3 matrix along with gold has reduced the average size of nanoparticle and has enhanced the nonlinear refractive index. The absorption spectra hints that there could be the possibility of surface plasmon resonance (SPR) overlap of Ag and Au as there is no prominent peak of Ag nanoparticles in the blue region. It is found that the sample doped with Au-AgNO3 has lesser bandgap energy compared to Au-AgCl and Au-AgI respectively which had thereby increased more NBO's in the matrix which in turn results in better nonlinear optical properties for Au-Ag NO3.

Indeno [1,2-b] fluorene-6,12dione (Indeno-fluorene) films were deposited on glass substrates by thermal evaporation technique. x-ray diffraction of the Indeno-fluorene films shows amorphous phase nature. Alternating current, AC conductivity was studied as a function of frequency and temperature within a range of 40 Hz-8 MHz and 303–423 K, respectively. The calculated value of the electron density of states (N(EF)) near the Fermi states at room temperature and frequency of 500 kHz was 8.73 × 1023 eV−1cm−3. In addition, parts of dielectric constant-real and imaginary were investigated at different temperatures. The relaxation process, relaxation time, activation energy, Coulomb height potential, and the extensive localized electronic states were studied. The normalization spectra of electric modulus elucidate that Indeno-fluorene thin films can be expounded by a non-Debye type of relaxation. The obtained data were discussed in terms of correlated barrier hopping model (CBH) and candidate Indeno-fluorene films for solar cells, transistor units, and electronic applications.

We synthesized a novel isatin hydrazone derivative 3-(((E)-3-ethoxy-2-hydroxybenzylidene)hydrazineylidene)indolin-2-one (IL) via condensation of isatin hydrazide with 3-ethoxy-salicylaldehyde in methanol. Then ZnO was chelated with the ligand (IL) to produce a novel ZnOIL complex. The characteristics of the IL and ZnOIL compounds were compared using various techniques, including nuclear magnetic resonance, ultraviolet–visible, infrared, and mass spectroscopy, and elemental analyses to confirm their chemical compositions. The optical properties of the IL and ZnOIL thin films were studied based on spectroscopic measurements of their absorbance, transmittance, and reflectance within the range of 300–2500 nm. The optical constants, dielectric parameters, and dispersion energies were determined and interpreted. The electronic inter-band transitions of the IL and ZnOIL films were characterized by indirect allowed transitions. The value of the optical band gap (Eg) was determined as 2.14 eV for the IL film, but chelation of IL with ZnO decreased Eg to 2.02 eV. The surface and volume energy loss functions were lower for ZnOIL compared with IL. The structural and the optical features of ZnOIL may be tuned, and thus it is a promising candidate material for applications in energy conversion and storage devices.

Many physical properties such as the average coordination number (CN), the compactness (δ), the overall bond energy (〈E〉), the cohesive energy (CE), the mean bond energy (E s), and the overall electronegativity difference (Δχ) as well as the degrees of ionicity (Ion) and covalency (Cov) were estimated theoretically. The chemical bond approach (CBA) was used to predict the type and proportion of the formed bonds in the studied glasses. Consequently, several structural and physical properties have been estimated. The results show that the studied glasses are rigidly connected, having an average coordination number increase from 2.41 to 2.61. Two approaches have been successfully used to estimate the band gap (E g) theoretically compared with the previously published experimental values for the Ge18Se82−xSbx (5 ≤ x ≤ 25 at. %) glasses. Values of E g decrease from 1.59 to 1.15 eV by an increase of the Sb content from 5 to 25 at. %. i.e. the wavelengths corresponding to E g values lie in the near-infrared range of spectra, which make these glasses candidates for the near-infrared applications. Furthermore, the ultrasonic longitudinal (v L ) and shear wave (v T ) velocities propagating through the glasses have been used to estimate the mechanical parameters such as the elastic bulk modulus, Poisson’s ratio, Young’s modulus, micro-hardness, and temperature of Debye. It was found that a change in slope occurs for various physical, mechanical, and structural properties near the stoichiometric composition (x ≈ 18 at. %) at which the glass structure consists of heteropolar bonds only.

In this study, a group of molybdenum boro-tellurite glass samples and their mechanical parameters and nuclear radiation shielding competencies were investigated. The amorphous structures of molybdenum boro-tellurite glasses were confirmed by XRD patterns. Synergistic positive effect of MoO3 reinforcement on gamma ray attenuation properties and mechanical parameters was investigated. For this aim, and in the energy range 0.015–15 MeV, the mass attenuation coefficients (MAC) had been computed by computational methods. At 0.015 MeV, the MAC values increase from 28.06 to 33.25 (cm2 g−1) as the MoO3 content increases from 0 to 30 mol %, while the half value layer values decrease from 4.84 to 3.88 (cm) at 15 MeV. The longitudinal ultrasonic velocity (VL) and shear ultrasonic velocity (VS), longitudinal modulus (L), shear modulus (S), bulk modulus (K), and Young’s modulus (Y) increase from 3450 to 3637 (m s−1), from 1994 to 2146 (m s−1), from 53.44 to 64.88 (GPa), from 17.86 to 22.58 (GPa), from 29.63 to 34.77 (GPa), and from 44.61 to 55.69 (GPa), respectively. The analysis of the shielding and mechanical indicates best protection of the explored glasses for γ-irradiation. Based on the analysis, the glass 30MoO3-70TeO2 with the maximum MoO3 addition indicated best γ-irradiation protection and mechanical parameters among the explored glasses.

As20Se65Tl15 films of thickness of 400 nm as a candidate of As-Se-Tl films were prepared by thermal evaporation technique under a vacuum of 10− 6 Torr. The aging of these films for 4 and 8 months and were studied. The as deposited films have amorphous nature and the aged films have (170) and (432) preferred nanocrystalline orientations. The crystallite size of 8 months aged films are 22 and 43 nm respectively. Within the wavelength range (200 − 1100) nm, optical parameters were measured and the optical constants were calculated within the visible range. Indirect electronic transition was dominated. The value of the optical energy gap, Egiopt increases with aging from 1.68 to 1.82 eV. The dispersion parameters were studied by single oscillator model. Aging process increases the values of N/m⁎ and Eo while decreases the values of n, e∞, eL and Ed. The obtained changes were attributed to structural enhancement and ordering due to aging process. The single oscillator model is used to describe spectrum of refractive index. Free carriers concentration makes a difference between e∞ and eL values. The calculated values of e1 are higher than the values of e2. The Optical conductivity as well as VELF and SELF were also studied.

This work reports on the effect of the increment of Fe2O3 in a network of phosphate glasses involving Al2O3, Na2O and PbO by DTA and Mössbauer techniques. The analysis of Mössbauer suggests oxidation of Fe2+ ions in the distorted bipyramidal to Fe3+ in the same site. This procedure creates non-bridging oxygens joined with Fe2+ octa that weakens the phosphate network whenever the Fe2O3 content increases. The thermal parameters of the phosphate network will be affected by this weakness. Thus, both the glass transition temperature (T gl ) and the crystallization peak temperature (T cp ) on the one hand and the activation energies for glass transition E gl and for crystallization (E gl and E cp ) on the other hand will decrease as a function of Fe2O3. This decrease will be discussed following Lasocka’s relationships that present a good correlation between T gl and T cp . Furthermore, the glass transition temperature (T gl ) was correlated with the glass fragility (m) and with the elastic parameters of the phosphate network such as the bulk (K) and shearing (G) moduli.

X-rays diffraction and scanning electron microscope were used to investigate the structural properties of tetraphenylporphyrin, TPP, which is polycrystalline in a synthesized condition. It turns to amorphous structure upon thermal deposition. Annealing temperature ranging from 295 to 473 K does not influence the amorphous structure of films. The optical properties of TPP were investigated using spectrophotometric measurements of the transmittance and reflectance at normal incidence in the wavelength range of 200–2200 nm. The absorption spectra were recorded in UV–visible region of spectra for the as-deposited and annealed samples show different absorption bands, namely four bands labeled as Q-band in visible region of spectra and a more intense band termed as the Soret band in near UV region of spectra. The Soret band shows its splitting (Davydov splitting). Two other bands labeled N and M appear in UV region. The film thickness has no influence on optical properties of films while annealing temperatures have a slight influence on optical properties of TPP films. The type of optical transition in as deposited and annealed conditions of films was found to be indirect allowed band-gap. Both fundamental and onset energy gap decreases upon annealing.

Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.

Amorphous chalcogenide of As–Se–Tl glassy alloys was prepared by melt quenching technique. Films were deposited on a transparent glass substrate using thermal evaporation technique. The optical characterization of thin As–Se–Tl films was studied by the analysis of transmission spectra, measured at normal incidence, in the spectral range 200–3000. The envelope method, proposed by Swanepoel, is a commonly used method for studying optical properties of films with uniform and non uniform thickness. Thickness values as well as optical constants, refractive index, Dispersion energy, Urbach and static refractive index or infinite wave length dielectric constant, are calculated using Wemple–DiDomenico model near infrared region using the envelopes of the transmittance spectrum of the films. The values of optical constants: absorption coefficient, Urbach tail, refractive index etc. have been determined. Urbach tail is estimated using Tauc's extrapolation and is found to increase from 0.69 to 0.91 eV with the Tl addition. This behavior of Urbach tail is interpreted in terms of Tauc's Model. Other optical constants are interpreted in terms of Wemple–DiDomenico model, chemical bond approach, electro-negativity difference of the atoms involved and cohesive energy of the system.

As20Se60Tl20 bulk material was prepared firstly then thermal evaporation method was used to prepare As20Se60Tl20 films. Illumination effect at room temperature for the mentioned films has been studied within the homogeneous glass-forming region. The prepared film samples were amorphous, this is depicted by X-ray chart. Optical properties have been studied using spectrophotometric measurements. The absorption edge was shifted to shorter wavelengths due to light exposure or photobleaching effect. It was found that the extinction coefficient and the optical band gap have opposite character after illumination.

Thermal evaporation technique was used to prepare As 20 Se 80-x Tl x films from bulk materials; (5 ≤ x ≤ 35 at.%). The effect of TI addition on the thermoelectric properties and mobility activation energy of As-Se-Tl chalcogenide semiconductors has been studied in the homogeneous glass-forming region through temperature range (300-380 K). The thermoelectric power, TEP had a positive sign over the whole temperature range investigated, indicating p-type conductivity for As 20 Se 80-x Tl x films. TEP activation energy, ΔE s could be calculated from TEP measurements. It was found that ΔE s decreases with increasing Tl-content and is found to vary between 0.814 and 0.517 eV. The mobility activation energy, ΔE Q could be calculated.

Thin films of As 20 Se 80− x Tl x ; ( 5 ⩽ x ⩽ 3 5 at % ) were prepared by thermal evaporation of the bulk materials. The effect of Tl addition on the electrical properties of As–Se–Tl chalcogenide semiconductors has been studied in the homogeneous glass-forming region through the low- and high-temperature range (173–373 K). The results indicated that the conduction in these glasses is through an activated process having two conduction mechanisms (band conduction in extended states and hopping conduction in localized states). The thallium in the As–Se–Tl ternary system tends to decrease the glass transition and melting temperatures and increase the DC conductivity in the amorphous phase. The activation energy for As 20 Se 80− x Tl x is found to vary between 0.9 and 0.64 eV. A comparison between computed and measured densities was performed. The measured density appeared to be smaller than the computed one. This difference is attributed to the transformation of the material to the amorphous nature.

The mechanism of incorporation of copper in amorphous films of Ge15Te85−x Cux (0≤x≤7 at.%) system and the effect of heat treatment are studied by measuring the dc conductivity in the temperature range (150–423 K). The results indicates that there are two conduction mechanisms. For temperature above 330 K, conductivity exhibits activated behaviour, while in low temperature range (T=150–300 K) conductivity exhibits non-activated behaviour. In the high temperature region, resistance and the activation energy have been calculated. The decrease in the activation energy on addition of Cu has been interpreted according to the Kastner model. In the low temperature region Mott's parameters have been evaluated and they are decreased with Cu content; the results in this region are interpreted following Mott's model.

Alternating current (AC) conductivity and dielectric properties of thermally evaporated Au/PtOEP/Au thin films are investigated each as a function of temperature (303 K–473 K) and frequency (50 Hz–5 MHz). The frequency dependence of AC conductivity follows the Jonscher universal dynamic law. The AC-activation energies are determined at different frequencies. It is found that the correlated barrier hopping (CBH) model is the dominant conduction mechanism. The variation of the frequency exponent s with temperature is analyzed in terms of the CBH model. Coulombic barrier height W m , hopping distance R ω , and the density of localized states N(E F) are valued at different frequencies. Dielectric constant e 1(ω,T) and dielectric loss e 2(ω,T) are discussed in terms of the dielectric polarization process. The dielectric modulus shows the non-Debye relaxation in the material. The extracted relaxation time by using the imaginary part of modulus (M'') is found to follow the Arrhenius law.

Thickness of 200 nm of NiTPP film is prepared by thermal evaporation technique under vacuum 10−6 torr as a candidate of nano metallo-tetraphenylporphine to study long aging. The prepared films are amorphous in nature while the aged samples were nano-structured with a crystallite size of 19 and 53 nm. An enhancement of crystallinity was seen after 6 months aging, while further aging showed structural stability. SEM micrograph confirms XRD results. Optical gap as well as optical constants and dispersion parameters are calculated; its values are increasing except the dispersion parameters are vice versa. The obtained changes are attributed to the enhancement of ordering because of aging time.